Tympan



TYMPAN Filed Oct. 150, 1959 R. SKIDMORE Nov. 20, 1962 3,064,330 TYh/EPANRiah Skidmore, Garland, Tex., assigner to John E. Mitchell Company,Dallas, Tex., a corporation of Missouri Filed Get. 30, 1959, Ser. No.849,913 5 Claims. (Cl.29124) 'Ihis invention relates to an attachmentfor a laminating machine. It is adapted for many uses, such as with alaminating machine of the type employing a large drum opposed by apressure roller, between which the sheets of material to be laminatedtogether are compressed. The speciic attachment involved here comprisesa section to be added to the main drum for spacing the material fromthat drum. The resulting raised surface is known in the trade as atympan. The main purpose of this attachment is to prevent the main drum,usually in the form of a cylinder, from becoming coated with glue. Theinvention more particularly relates to such an attachment means which iscomprised of a plurality of separable units.

While many uses for the invention will occur to those skilled in theart, and the invention is not intended to be limited to use with alaminating machine, it is described in that environment forillustration.

A typical example of the type of laminating machine with which thepresent invention is devised for use is the type designed for gluing asheet of paper to a sheet of cardboard. Such a machine might be used tocomplete the construction of an advertising board, for example, whereinthe advertising design has been eiected upon the paper and it is desiredto make that paper more rigid by the addition of a cardboard backing.Such a laminating machine, while complicated, incorporates at least alarge main cylinder against which one of the sheets to be laminated isplaced. After this sheet has been coated with glue and before the maincylinder has rotated far enough to approach a rubber-covered pressureroller, the second sheet is placed with a leading edge adjacent theleading edge of the rst sheet. Thereafter, the two are squeezed betweenthe main cylinder and the pressure roller and an even laminatingoperation is performed.

In these laminating machines, a roller, partially submerged in a tub ofglue, is often used to apply the glue. Even when other glue applicatorsare used, they, like the glue roller, are continually covered with glue.If no raised surface were used beneath the paper sheets, the entire drumsurface would be coated as it passed the glue applicator so thatsucceeding sheets placed on the drum would be stuck there by glue. Anadditional reason for the raised surface, or tympan, is that during thepressing or squeezing operation, occasionally an amount of glue issquirted out from between the sheets of material and deposited upon themain cylinder. Subsequently, when a new operation is to be performed andone of the sheets is placed against the cylinder, the glue spatteredthereon by the preceding operation interferes with the removal of asubsequent one.

Tympans have been developed heretofore for elevating or spacing thesheets from the main cylinder. As these spacing means are all slightlysmaller in surface area than the sheets to be laminated (there may bebetween 1/2 and 1/8 inch overhang), no glue will be spread upon thetympan. Likewise, since the glue applicator is spaced y ansias@ PatentedNov. 20, 1962 from the main drum, glue will not be applied to it,either. The glue which squirts out from between the sheets will fall noton the spacing means but onto the main cylinder since the laminatedsheets cover substantially the entire surface of the spacing means.Then, when subsequent sheets are placed upon the spacing means, they arenot stuck to that spacing means by the extra glue.

The size of the spacing means, or more particularly the area of theraised surface of the spacing means, must be varied according to thesize and area of the material to be laminated. For the spacing meansheretofore employed, the only way of varying the area of the surface hasbeen to replace that spacing means with a different one. It is animportant object of the present invention to provide a raised-surfacespacing means for use upon a laminating machine, which spacing means iscomprised of a plurality of tympan units to which may be added orsubtracted additional units for varying the effective surface of thespacing means (or tympan).

Although in a general sense, spacing means have been used before for thesame purpose as that to which the present invention is directed, theseprior spacing means have comprised one or more layers of cloth,paperboard, etc., which have been discarded after one or two usages.This cloth or paperboard tympan must be held in place by either amechanical device at the ends or by glue. The disadvantages of gluinganything to the main cylinder are obvious, and it is another object ofthe present invention to provide a tympan which is held to the maincylinder by quickly releasable means, speciiically by magnetic means. v

Still another object of the invention is to provide a tympan which has ahard, yet somewhat resilient, surface for long life. The surface of thepresent tympan comprises a durable resilient material such as neopreneor rubber construction.

Another object of the invention is to provide a plurality oi' tympanunits which include magnetic holding means for attachment to a maincylinder of a laminating machine, which may be added to or removedaccording to the size of the material to be laminated.

Another object of the invention is to provide a tympan comprised of aplurality of units, each unit including means for aligning it withrespect to the others.

Still another object is to provide a tympan comprised of a plurality ofunits of a minimum number of diierent sizes, which units may be combinedin various combinations to form any of a wide range of possible tympansizes. A corollary object is to provide tympan units in various sizes inwhich these sizes have been so computed that a low inventory maintainedby a supplier will, nevertheless, permit a complete inventory.

Gther objects and advantages will be apparent to those skilled in theart.

In the drawings:

FIGURE 1 is a plan view of a tympan unit;

FIGURE 2 is a side elevation taken lengthwise of the unit of FIGURE l;

FIGURE 3 is a bottom view of the tympan unit;

FIGURE 4 is a view in section tasen along the lines 4 4 of FIGURE l;

FIGURE 5 is a view in section taken along the lines 5-5 of FIGURE 2;

FIGURE 6 is a View showing a plurality of tympan units arranged on thesurface of a cylinder, with the cyl- Y mder shown somewhat schematicallyand in section;

FIGURE 7 is a bottom view, partially broken away, of a modification ofthe invention; and

FIGURE 8 is a view in section taken along the lines S-S of FIGURE 7.

Referring now to the drawings, each tympan unit is designated generallyby the numeral 20. There is a chanhel member 21 extending the length ofthe tympan unit, but it is not as wide as that unit. The channel haslegs br ang'e's 22 and 23 adapted to extend toward the cylinder to whichthe Atympan unit is to be attached. The channel member 21 is constructedof a material which is mag- 'netieally conductive, such as iron orsteel.

Placed between the legs or flanges 22 and 23 of the channel member 21,is a magnet 24. The magnet 24 need not be as long as the channel member21, although it may be, The magnet 24 may beV thought of as having a topsurface 25 and a bottom surface 26, and the distance between the twoshould be less than the height of the flanges 22 and 23. The reason forthis preference is that since the'tympan units are to be attached to acylindrical surface, is best that there be a clearance between themagnet 24 and the cylinder so that the flanges 22 and 23 will makecontact with that cylinder. Otherwise, the clearance or differencebetween the thickness of the maghet 24 and the flanges 22 and 23 Vshouldbe such that the clearancvebetvveen the magnet and the cylinder is aminimum; The magnet 24 may be attached to the channel 21 gle or othei well known means, although if no attaching fneans is provided, the magnetwill remain within the channel 21 de to it's lown'attrac'tion towardthat channel.

'Ihe'is a plastic body section 27 cast directly on or othetwise securedto the top of the channel member 21. The body member 27 Ais at least aslong as the channel member 25 and, in addition, it is somewhat wider.Thus, `there isA an overhang 2S, and another one 29, beyond each ange 22and 23 of the channel member 21.

Finally, the body member 27 has secured to its top surface 30 aresilient face 31. The face 31 has the same length and width dimensionsas the top 39 of the body member 27. It can be observed from FIGURE thatboth the top surface 30 of the body member 27 and the face 31 areparallel and that the face 31 is l'gently arcuate to form what might becalled the working surface of the main cylinder of a laminating machine.Thus, there will be uniform pressure applied to the face 31 as it rollspast a pressure roll.

The tympan units 20 may be used in any combination. For example, FIGURE6 illustrates an end view of three row'srof tympan units magneticallysecured to a cylinder Since the body member 27 with its face plate 31overlaps the channel member 21, the face plates 31 of the lseveraltympan units 2i) can abut one another without interference from thechannel 21 and its magnet 24.

The tympan units 20 will cling to the metal cylinder because of themagnet 24. Since the magnet 24 is attached directly to themagnetically-conductive channel member 25, its magnetic field will beinduced in the flanges 22 and 23. It is the anges 22 and 23 which makephysical contact with the cylinder 85.

Any of the tympan units 20 can be removed from the cylinder and laterreplaced by others, according to the size of the sheets to be laminatedby the machine.

Obviously, as can be appreciated from FIGURE 6, if a sheet of paper isplaced upon the tympan comprising the combination of tympan units 26,and the drum 35 is rotated past a glue roller, glue will be applied tothe paper surface. However, the glue will not contact the drum surfacebecause of the spacing feature of the tympan. Also, if some glue issqueezed out durihg a laminating operation, that glue will fall onto thedrum 35 rather than on the tympan sections 20. This, of course,providing the proper number and arrangement of tympan units has beenemployed to assure the slight overlap of paper beyond the surface areaof the tympan as has already been explained. rFhus, when that laminatedmaterial is removed and another laminating process is to be performed,there will be no glue upon the raised surface defined by the tympansections 2f?.

A modification of the invention is shown in FIGURES 7 and 8. The maindifference between the tympan units shown in these gures, from thosealready described, is that they comprise a plurality of bar magnetsimbedded in a plastic material. Thus,fin FIGURES 7 and 8, there is showna tympan unit 4) having a plastic block `4i. Molded into the plasticblock 41 are a pair of angle members 42 and 43, a plurality of barmagnets 44 and a sheet of fibre insulation 45. As was true with thetympan unit 2t), the unit 40 has a resilient face plate or block 46attached to the plastic 41.

The embodiment of FIGURES 7 and 8 includes a means for aligning thetympan units in even rows. rl`his means comprises a plug 47 at one endof the unit 40 and a socket 48 at the other end. Therefore, when aplurality of tympan units 40 are to be placed together on a cylinder,the position of each relative to the others will be dictated by thepositions of the plugs `and sockets 47 and 4S.

Because the plug and socket arrangement helps maintain alignment of theseveral tympan units, the plugs and sockets could be included with theembodiemnt Vof FIG- URES 1 through 6.

Although the specific size of the tympan units may beV varied from thefollowing dimensions, those dimensions are included here because theyrepresent six tympan unit sizes which will permit the assembling of anydesired tympan size ranging from 11" by 14 to 48" by 72 (the upper limitbeing imposed by the maximum capacity of a standard laminating machine).The unit sizes which have been found to make possible this versatilevariation are 1% x 21/2, 1% x 2%, 1% x 31A, 1% X 21/2, 1% X 2% and lS/s"x 3%. These six sizes can be quickly combined end to end and in rows inthe required number to provide a completed tympan of a desider size.Because only six basic Sizes are involved, an extremely low inventory ofparts is possible.

What is claimed is:

1. In a machine for laminating together a pair of material sheetswherein the machine has a drum lfor supporting a means defining a raisedsurface, the means defining the raised surface comprising: a pluralityof separate units, each having a face defining a portion of a cylinderwith the side edges of the face defining a rectangle, and magnetic meansfor releasably attaching a plurality of the units to the surface of thedrum with the edges of adjacent units abutting one another to define anoverall, continuous raised surface of variable size and shape accordingto the number and relative positions of the units, the magnetic meanscomprising a pair of spaced magnetic flanges connected to each unit andextending from each unit in a direction away from the face of the unitparallel to the axis of the drum, the anges being of magnetic material,and magnetic means between and in magnetic communication with thefianges for inducing magnetism in the flanges.

2. The combination of claim 1 wherein the portion of each unit definingits face is resilient.

3. A combination of tympan units for application to the metallic surfaceof a cylindrical drum to provide a raised surface beyond the surface ofthe drum, each tympan unit comprising a body having a top, four sidesand a bottom, the top being rectangular at its edges and the four sidesextending downwardly from the edges of theV rectangular top, the surfaceof the top between its edges being arcuate of a radius equal to theradius of the drum plus the total height of each tympan unit, a pair ofmagnetic metal plates extending downwardly from each tympan unit atleast far enough that the lower edges of the metal plates project belowthe bottom of the body, the plates being spaced from one another and thelower edges of the plates being parallel to an element of the arcuatetop of the body, and a permanent magnet mounted between and in contactwith each pair of plates, whereby individual ones of the tympan unitscan be attached to the surface of the drum in combination with variousmembers of other tympan units to vary the size of the total tympan topsurface.

4. The combination of claim 3 wherein there are articulate interlockablemeans between adjacent tympan units to lock the units together in rows.

surface of the body of each tympan unit is dened by a resilientmaterial.

References Cited in the file of this patent 5. The combination of claim3 wherein at least the top 10 2,902,930

UNITED STATES PATENTS Leppke et al. Apr. 12, 1927 Morrison Feb. 11, 1941Strmme Dec. 18, 1956 Hurlbut Sept. 8, 1959

